About hash maps / dictionaries

hashMaps.kt

/**
Immutable hash map/dictionary
**/ 
val contacts = mapOf("Tom" to "0780","Peter" to "4784","Derrick" to "6780" )
println(contacts)
println(contacts["Tom"])
println(contacts.get("Peter"))
println(contacts.values)
    
/**
Mutable hash map/dictionary
**/
val contactsMap = hashMapOf("Gad" to "8745")
contactsMap["Ronny"] = "3245"
contactsMap.put("Bonny", "4545") 
println(contactsMap)
contactsMap.remove("Gad")
println(contactsMap)

//For-loop
for((k,v) in contactsMap){
   println("$k, $v")
}
   
val nums = arrayListOf(3,2,1,4,6)
for(num in nums){
   println(num)
}